Ken Simons (Boston University) has this post at PrawfsBlawg, for those seeking alternatives or supplements to the trolley problem. In part:

I do not suggest that the purpose/ knowledge distinction is the only source of public outrage over the Saints' "bounty" system. Another possible source is the egregiously quid-pro-quo nature of paying a bounty. Any bounty system makes it uncomfortably clear how much the NFL rewards violence. But I doubt that the payment of bounties is the whole explanation. Suppose, for every "hard hit" or every successful sack of a quarterback, a player received a financial reward. I doubt that serious outrage would be the reaction.